Operational Drift: Why Validated Fatigue Induction is the Missing Link in Nature Restoration Research

Nature-based interventions are increasingly promoted for cognitive benefits, yetsystematic reviews consistently report small effects, high null rates, and substantialheterogeneity. I argue this reflects operational drift from the conditions that restorationclaims require. While Attention Restoration Theory posits recovery from fatigue, only29% of studies in the most recent meta-analysis explicitly induced fatigue, and thosethat did often used brief, low-load tasks unlikely to produce measurable impairment.This creates an unfalsifiable paradigm: without verified pre-exposure deficits, positiveresults cannot distinguish restoration from arousal shifts or preference effects, whilenull results cannot distinguish "no effect" from "no deficit to recover from." I proposethat rigorous restoration protocols require four elements: validated fatigue induction,manipulation checks confirming objective impairment, appropriate control conditionsincluding a neutral third arm, and outcome measures with established sensitivity todetect cognitive fatigue.